Fill in the blanks. (12)
1. The car speed is equivalent to the train speed, and the unit is ().
2.3 tons = () kg 154 minutes ()
3. A circle has a diameter of 4cm, a circumference of () and an area of ().
4. 16 is ()% of 20, ()% more than 16.
5. () 8 = = 0.5 = ()% 2 (): () .60% of 6.80 is (); 80% of () is 60.
7. In 3:2, if the former item is added with 6, the proportion should remain unchanged, and the latter item should be added with ().
8. Fill in ">,<, ="
2.2×2.2
8÷ 12O66.7%
9. During the New Year's Day, a sweater with the original price of 100 yuan in a shopping mall was only sold to 85 yuan. After calculation, this sweater is sold at the price of ().
10. Cut a piece from a square paper with a side length of 10 decimeter.
The largest circumference is () decimeter, and the area is () square decimeter.
1 1. Coins have 2 cents and 5 cents * * 18, a ***6 yuan dollar. There are () nickels.
12. Divide a circle with a diameter of 4 cm into several equal parts, then cut it open and put it together as shown on the right. The perimeter of the combined figure is () cm longer than the original circle.
Second, judge. (5 points)
1. The ratio of boys to girls in one class is 7:8, and boys account for the whole class. ( )
2. The circumference of a circle with a radius of 1 cm is equal to its area. ( )
3.A is greater than B, that is, B is less than A ()
4. A batch of trial-produced products, 120 pieces are qualified, 30 pieces are unqualified, and the qualified rate is 80%. ()
The ratio of circumference to diameter of all circles is equal. ( )
Third, choose the serial number of the correct answer and fill it in brackets. (5 points) 1. The number of A is 18, the number of B is 18, and the number of A is () B.
First, greater than
B, less than
C is equal to
2. Add hundreds of semicolons after the number A (A is not equal to 0), and the number will be ().
I. Enlarged by 100 times
B, reduced by 100 times.
C, unchanged
3. Mr. Wang has deposited 3,000 yuan in the bank with a fixed term of 2 years and an annual interest rate of 2.25%, and will receive the principal and after-tax interest of * * * () yuan at maturity.
3000 pounds
b、3 108
c、 108
4. The figure with the least symmetry axis is ().
A, round
B, rectangle
C, square